From that opening I just expected that the idea that you had to use two would be a frustratingly widespread misconception and completely wrong. Given that I had that misconception, that the UX implies that it’s the case (remove one and it stops playing music), and it is apparently completely wrong, I’d say the parent was pretty spot on.
But saying "I'll just address this point, because it is categorically incorrect" was unnecessarily aggressive. With that opening, I think people expected a solution with no caveats.